1. Field of the Invention
The present invention relates to hay balers in particular, although other, related, applications may be apparent in light of the following description.
There has been a significant evolution in the processing of hay and straw since the very early use of dump rakes, hay loaders pulled behind wagons and the like. In order to store hay and straw more efficiently, methods were devised for compressing the hay into bales of uniform size, tying the bales in their compressed state in order to hold them, thereby permitting their efficient storage and handling for later use. Early hay balers (and it will be understood that the use of the term "hay" is intended to be inclusive of straw and other products which may be baled and tied, with the possible exception of cotton) required several men to operate. The baler, whether pulled by a tractor or self-propelled, moved along a windrow of products such as hay, picked up the windrow, compressed it and forced the compressed material into a chute of predetermined size. One man rode the baler upstream of the chute and would, periodically, insert wooden blocks into the shute to separate the bales. Wire, rather than twine, was used for tying purposes, and two men riding on either side of the shute would insert wires on one side and tie off bales on the other. The operation was labor intensive, obviously costly, and relatively inefficient.
As the evolution continued, first with early mechanical wire tying devices and later with twine, the baling operation was reduced from a five or six man operation to a one man operation. However, due to variations in uniformity, quality, diameter and other characteristics of the binding medium, together with the just plain complexity of the knot tying devices, malfunction of the tying device was not uncommon. Such malfunctions would include jamming of the knotting devices, failure of the knotting device to effect an adequate tie, breakage of the twine itself and an assortment of other maladies, many of which would be undetectable to the operator until he had proceeded for some distance. As a result, bales would be ejected from the baler either loose, or in such infirm condition that handling would result in breakage, all of which would result in loss of time and reduce the efficiency of the entire operation.
2. Overview of Related Art
The fallibility of twine tying devices is not a new revelation, and has been the bane of the baling industry since the inception of the adoption of the mechanical tying device. While several inventors have sought out the solution, the problem is ever present, and until the advent of Applicant's invention, inadequately addressed.
Baling devices come in several configurations, but the most familiar include the large cylindrical bales
represented by the baler of Drutel U.S. Pat. No. 4,624,179 and, of course, the bale having the square or rectangular cross section such as that depicted in Gordon, et al. U.S. Pat. No. 4,269,116.
The Gordon patent in recognition of the problem of potential malfunction of the tying device, uses a rather complicated sensing needle, timer and alarm for warning an operator in the event that a tie has not been adequately completed. The device does not, however, provide any kind of warning to the operator until there is already a malfunction in the tying device and a tie has not been adequately completed. Accordingly, the operator does not have any warning until one or more "loose" bales have been generated.
Yatcilla, et al. U.S. Pat. No. 4,196,661 describes yet another effort to provide notice to the operator of a malfunction, but, once again, the device relies wholly upon broken twine as the trigger for the warning. If, for example, the twine broke but became entangled in the mechanism, or did not break but, likewise, did not effect a tie, the warning mechanism would not be triggered and the purpose of the device would be defeated. Moreover, in more modern balers where there is a single operator, typically located forward of the twine tying mechanism by a considerable extent, whether in a self-propelled or tractor pulled device, the raising of a flag, as suggested by Yatcilla, may or may not provide warning to an operator. In all probability, it would not be where the operator is facing forward and concentrating on keeping the baler on the windrow.